Vacuum centrifugal jewelry making machine



Oct. 25, 1966 A. R. cEcERE 3,280,434

VACUUM CENTRIFUGAL JEWELRY MAKING MACHINE Filed April 22, 1964 l 4 sheets-sheet 1 FROM ELEC. PWR. .SUPPLY FROM ELEC P WR.

.SUPPLY HMO/gy ecere Oct. 25, 1966 A. R. CECI-:RE 3,280,434

VACUUM CENTRIFUGAL JEWELR-'IY MAKING MACHINE Filed April 22, 1964 4 sheetssheet 2 A. i!m

Oct. 25, 1966 A. R. CECERE 3,280,434

VACUUM CENTRIFUGAL JEWELRY MAKING MACHINE Filed April 22, 1964 4 Sheets-Sheet 3 n/)ong ecere /WTRN 5.

Oct. 25, 1966 A. R. CECERE 3,280,434

VACUUM CENTRIFUGAL JEWELRY MAKING MACHINE Filed April 22, 1964 4 Sheets-Sheet 4 ATTRNYS United States Patent O 3,280,434 VACUUM CENTRIFUGAL JEWELRY MAKING MACHINE Anthony R. Cecere, 60 Fox Place, Hicksville, Long Island, NY. Filed Apr. 22, 1964, Ser. No. 361,732 15 Claims. (Cl. 22-65) This invention concerns an improved centrifugal casting machine for making jewelry.

In prior centrifugal casting machines used in making jewelry it has heretofore not been possible to mold jewelry pieces of less than 0.060 of an inch. This has been a considerable disadvantage since there are many jewelry designs involving ine filigree Work and other ne `details having thicknesses or Widths of approximately 0.010 of an inch which cannot be reproduced in conventional centrifugal casting machines.

It is a principal object of the invention to lprovide an improved centrifugal casting machine of simplified structure including means for temporarily maintaining mold chambers in rotating molds under vacuum.

A further object `is to provide an improved jewelry casting machine which is more economical in construction, easier to operate, and productive of finer castings than has heretofore been possible of attainment with conventional centrifugal casting machines.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIG. 1 is Ia side elevational view of a machine embodying the invention.

FIG. 2 is a vertical sectional view taken on line 2 2 of FIG. l.

FIG. 2A is an enlarged fragmentary sectional View similar to portions of FIG. 2, showing parts in working position.

FIG. -3 is ian enlarged cross-sectional view taken on line 3 3 of FIG. 2.

FIG. 4 is an enlarged perspective view of an open vacuum vessel, portions being broken away.

FIG. 5 is a reduced sectional View taken on line 5 5 of FIG. 4, with the vacuum vessel shown closed.

FIG. 6 is a side View of a metal feeding pot shown in operating position, parts being broken away.

FIG. 7 is :an enlarged perspective view partially in section of mold plates employed in the machine.

FIG. 8 is a plan View of part of an article of jewelry as made by the machine.

FIG. 9 is an enlarged sectional view taken on line 9 9 of FIG. 8.

Referring rst to FIGS. l-S, there is shown a centrifugal casting machine 10 including a stationary stand or frame 11 on which is mounted a motor 12 with axially vertical shaft 14. The motor is supported and held xed by a bracket 16 on a platform 18. The motor is energized via cables 17 and is controlled by switch 19. On shaft 14 is a pulley 20 driving an endless belt 22 entrained on another pulley 23 carried by an axially vertical splined shaft 24. This shaft 24 is journaled for rotation on a bearing 25 carried by the platform 18. Slidably engaged on the splined shaft is an internally grooved axial ybore 26 of a Vertical shaft 28. When shaft 24 rotates the shaft 28 rotates with it. Shaft 28 is keyed by a pin 29 to a flange 30 rotating on ball bearings 32. The bearings are carried on the upper end of a sleeve 34 through which shaft 28 extends. The axially vertical sleeve has a rack gear 36 vertically disposed and engaged with a spur gear 38.

Gear 38 is mounted on a horizontal shaft 40 journaled in a bearing 42 on the frame 11. Handles 44 at the outer end of shaft 40 permit this shaft to be manually turned. When shaft 40 is turned, the sleeve 34 is axially elevated ibut ldoes not rot-ate. Shaft 40 is rotatably engaged at its inner end in a stationary casing 46 carried by brackets 48 secured to the platform 18; see FIGS. 1, 2 and 3. Sleeve 34 moves axially in a cylindrical recess 47 in the casing.

At the upper end of shaft 28 is a horizontal circular table 50. This table rotates with shaft 28. At the periphery of the table in diametrically opposite positions are upright arms 54 carrying pivotable cylindrical weights 55. The weights have axial posts 56 pivotally engaged by pins 58 near the upper ends of the arms 54. Inner ends 57 of the posts project inwardly of the arms so that when the table is rotating the posts assume horizontal positions .as shown by dotted lines in FIG. 2, while the Weights assume elevated vertical positions. In the horizontal positions of the posts, their inner ends 57 bear down on a circular massive, pressure plate 60. 'Between the plate 60 and the table 50 is disposed a pair of removable disk-like mold plates `62, 64 made of suitable mold material such as hard rubber. The rnold plates may rest on protective mat or plate 61 on the table.

In the facing sides 63 of the mold plates are facing indentations 65 defining mold cavities or chambers which can receive molten metal for casting articles of jewelry. The facing sides are formed with grooves 66 for passing molten metal from a central hole 67 in upper plate 62 to the indentations 65.

The upper plate 60 has a cylindrical nipple 72 in which are resilient sealing rings 68 and 69 mounted in annular support anges 70. The rings 68, 69 extend radially inward of the nipple 72. The rings are held in the nipple by an annular flange 74 at the upper end of the nipple and by a flange ring 75 secured in a hole 77 in the center of plate 60; see FIGS. 2 and 2A. The upper end of shaft 28 is journaled in a bearing 71 on platform 73. The sealing rings `68 and 69 'are preferably made of silicone material, polytetrailuorethylene, or other equivalent material which is tough, resilient, resistant to heat and abrasion, and which has a smooth, self-lubricated surface for serving as a thrust bearing element.

On the top of frame 11 is a horizontal platform 79 supporting a vacuum vessel 80. This vessel has a cylindrical pot-like base 81 and cover 82. The flat bottom 83 of the base is secured to the platform by a weld 84. The base bottom has a hole 85 offset radially from the center of the flat bottom. Attached to the bottom of the base by a weld 86 is a short tube or ring 88. This ring is axially aligned with hole 85. The ring extends through a hole 89 in the platform 79. The ring has a cylindrical bottom end 98. Secured in the ring by `a setscrew 92 is a tube 93. This tube is axially aligned with hole 85 in the base bottom. The tube 93 fits tightly in the ring 88 to provide a hermetically sealed joint thereat.

gTube 93 is axially aligned with nipple 72 and when the plate 60 is raised to the dotted line position of FIG. 2, the nipple is hermetically sealed by contact with resilient rings 68, 69 in the nipple. The upper end of the nipple then abuts the flat bottom of end of ring 88.

In the cylindrical base 81 is a stationary funnel 98 held by a bolt 99. The funnel opens into tube 93 through hole 8-5. A cylindrical Crucible 100 is tiltably carried by a horizon-tal shaft 104 extending axially through the side wall 97 of the pot. A handle 106 on the outer end of the shaft 104 permits the Crucible to be tilted from its normal upright position shown in FIGS. 2, 4 and 5 to the inclined position shown in FIG. 6. An opening 105 in one end 107 of the crucible serves to pass molten metal M into the funnel 98. The metal can be illed through upper open neck S from a ladle L or other .suitable utensil, when the pot is open. The metal M in the crucible is kept in Ia molten condition by heater coil 112 around the Crucible. The coil is energized via electric cables 114 attached toy a connector 116 extending through the side of the pot. power plug 115 is connected to connector 116.

The base 81 of the vessel 80 has an upper annular flange 117 with projections 118 on which engage depending inwardly turned fingers 119 of annular flange 126 of the cover 82. A valve 122 on top of the cover closes the interior of the closed vessel oli from the outside atmosphere. This valve has a handle 123 for opening and closing the valve. A pipe 125 is connected to the side 97 of the base -81 and opens into the interior of the vessel. This pipe terminates at a remotely -located vacuum pump (not shown). A vacuum gauge 126 connected to pipe 125 indicates the air or gas pressure inside the vessel. The cover 82 has a handle 128 which can be used to turn the cover for disengaging the lingers 119 from projections 118 so that the cover can be removed. A gasket ring 129 on iiangev 117 seals the base and cover.

In operation of the machine, the crucible 190 can be filled with molten metal while the crucible is axially horizontal as shown in FIG. 4. The heater 112 will be energized to keep the metal in molten condition. The cover 82 will then be applied to the base S1 to close the vessel. Valve 122 will be closed.

A pair of mold plates 62, 64 will be placed on table 50 which is then in the lowered position of FIG. 1. Plate 60 is placed on plate 62. The handles 44 will be turned to elevate the table and mold plates. Tube 93` will enter nipple 72 and will be hermetically sealed thereat by rings 68, 69. The motor 16 will be started to rotate the table 50, mold plates 62, 64 and plate 60. The weights 55 will rise and the inner ends 57 of posts 56 will press down on the plate 60 to hold the plates 60, 62 and 64 together. The air will then be exhausted via pipe 125 from the vessel and from the mold cavities 65 defined between the superimposed plates 62, 64. The handle 108 will then be turned to tilt the crucible 106 as shown in FIG. 6, so that the molten metal M pours into funnel 98, then through the funnel and tube 93 to mold chamber 67, grooves 66 and the mold cavities 65. The metal will be effectively distributed in all the radially arranged cavities as the table 50 and plates 60, 62, 64 are turned at high speed. The vacuum is maintained in the vessel and -mold plates until the required amount of molten metal has been poured into the mold plates and has been distributed in the mold cavities. The valve 122 is then opened while the vacuum pump is turned off, and the table 50 is then lowered to separate plate 60 from tube 93. The plate 60 can then be removed. When plate 62 is lifted ot of plate 64 ias shown in FIG. 7, the cast pieces P can be removed from the mold cavities. It will be noted that the cast pieces reproduce even the very inest details D from the mold cavities. As clearly shown in FIGS. 8 and 9, a thin filigree article P simulating a butterfly wing can be reproduced in such line detail as to require no machining or tiling of details to complete it, other than removal of sprues S. Two pieces P and P' may be joined together with a central cast piece P to form a complete butterfly ornament.

The invention thus makes it possible to reproduce very thin, finely detailed cast jewelry rapidly, economically, and efficiently.

While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. Acentrifugal casting apparatus, comprising: a frame, a stationary vacuum vessel on said frame, said vessel having Ia bottom opening, a -funnel in said vessel communicating with said opening, a tube extending axially downward from said opening for receiving molten metal from the funnel, a Crucible in said vessel tilta-bly mounted for pouring molten metal into the funnel, heating means in the crucible for keeping the metal molten in the crucible, means for maintaining a vacuum in said vessel, a table disposed below and parallel to the bottom of the vessel, mold plates supported on said table, said mold plates having cavities therein, means for elevating and lowering `the table with respect -to the vessel, means for rotating the table in all positions of elevation with respect to the vessel, a massive pressure plate supportable by said mold plates on the table, said pressure plate having a nipple extending axially upward in axial alignment with said tube, sealing means -in said nipple for maintaining a hermetic seal with said tube while the plate rotates with the table :and mold plates, whereby mol-ten metal deposited into the funnel will run into the cavities in the mold plates impelled by gravity and centrifugal force as the table, pressure plate and mold plates rotate, and means on :the table for automatically engaging land holding the mold plates while the table rorates and for automatically releasing the mold plates when the table is stationary.

2. A centrifugal casting :apparatus for casting jewelry pieces reproducing very line mold details having widths approximating .010 of an inch, comprising: 'a fra-me, a stationary vacuum vessel on -said frame, said vessel having a bottom opening, a funnel in said vessel communieating with said opening, a tube extending axially downward from the bottom of the vessel hermetically sealed therewith and communicating with said opening and funnel, a crucible in the vessel til-tabily mounted for pouring molten metal ,into the funnel, means operatively connected to the Crucible for tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for crea-ting a vacuum in the vessel and for relieving the vacuum therein, a table disposed below and parallel to the bottom of the vessel, means for elevating and Ilowering the table with respect to the vessel, means for rotating the table in fall posi-tions of elevation thereof with respect to the vessel, mold means on the table for connecting with said tube to receive molten metal therefrom while the table rotates and for maintaining a hermetic seal therewith, and means on the table for automatically engaging and holding said mold means on the table while the table rotates and for automatically releasing said mold means when the table is stationary.

3. A centrifugal casting apparatus for casting jewelry pieces reproducing very fine mold details having widths approximating .G10 of `an inch, comprising: -a frame, a stationary vacuum vessel ron said frame, said vessel having a bottom opening, a funnel in said vessel communieating with said opening, a tube extending -axially downward from the bottom of the vessel hermetically sealed therewith Iand communicating with said opening and funnel, a Crucible in the vessel tiltabily mounted for pouring molten metal into the funnel, means operatively connected to the Crucible for til-ting the same, heating means in the Crucible for keeping the metal molten in the crucible, means for creating a vacuum in the vessel and for relieving the vacuum therein, a table disposed below and parallel to the bottom of the vessel, means for elevating and lowering the table with respect to 'the vessel, means for rotating the table in all positions of elevation thereof with respect to the vessel, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold pla-tes, sm'd pressure plate having an axial nipple extending toward the vacuum vessell, said nipple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said passage communicating with said central hole, sealing means in said nipple for maintaining a hermetic seal with said tube while the pressure plate rotates with the table and mold plates, whereby molten metall deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold plates and pressure plate rotate.

4. A lcentrifugal casting apparatus for casting jewelry pieces reproducing very tine mold details having widths approximating .O of an inch, comprising a frame, a cylindrical pot-like base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with ysaid base, said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively connected to the crucible for tilting the same, heating means in the crucible for keeping the metal molten in the Crucible, means for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve me-ans on the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, means for rotating the table, means for elevating and lowering the table independently of the tablle rotating means so that the table rotates in all positions of elevation thereof, a pair of separable mold .plates on the table, said mold plates having radially arranged mold c-avities therein, one of said mold plates having a centrali hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nip-ple extending toward the vacuum vessel, said nipple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said passage communicating with said central holle, sealing means in said nipple for maintaining a hermetic seal with said tube while the pressure plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold pl-ates and pressure plate rotate.

5. A centrifugal casting apparatus for casting jewelry pieces reproducing Very line mold details having widths approximating .010 of an inoh, comprising a frame, a cylindrical pot-like base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a Crucible in the base ti-ltably mounted for pouring molten metal into the funnel, means operatively connected to the Crucible for tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve means on the cover for relieving the vacuum in the vessel, a table rotatably supported below and paral- -lel to the bottom of the base, an axially vertical first shaft connected to said table for rotating the same, gear means engaged with said shaft for elevating the shaft and table, motor means, a second shaft rotatably driven 'by said motor means, said first shaft being slidably and nonrotatably engaged with `said second shaft in all positions of elevation of the rst shaft, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central h-ole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nipple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said passage communicating with said central lhole, sealing means in said nipple for maintaining a hermetic seal with said tube while the pressure plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold plates and pressure plate rotate.

6. A centrifugal casting apparatus for casting jewelry pieces reproducing very tine mold details having widths approximating .010 of an inch, comprising: a frame, a stationary vacuum vessel on said frame, said vessel having a bottom opening, a funnel in said vessel communicating with said opening, a tube extending axially downward from the bottom of the vessel hermetically sealed therewith and communicating with said opening and funnel, a cruc-ible in the vessel tiltably mounted for pouring molten metal into the funnel, means operatively connected to the Crucible for tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for creating a vacuum in the vessel and for relieving the vacuum there-in, a ta'ble disposed below and paralle-l to the bottom of the vessel, means for elevating and lowering the table with respect to the vessel, means for rotating the table in all positions of elevation thereof with respect to the vessel, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nip-ple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said passage communicating with said central hole, `sealing means in `said nipple for maintaining a hermetic seal with said tube while the pressure plate rotates with the table `and m-old plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled 'by gravity and centrifugal force as the tab-le, mold plates and pressure plate rotate, and means on the table impelled by centrifugal force for holding the mold plates and pressure plate on the table when the table rotates and impelled by gravity for releasing the mold plates and pressure plate when the table is stationary.

7. A centrifugal casting apparatus for casting jewelry pieces reproducing very tine mold details having widths approximating .010 of an inch, comprising a frame, a cylindrical pot-like 4base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a bottom openin-g, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively connected to the crucible for tilt-ing the same, heating means in the crucible for keeping the metal molten in the Crucible, means for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve means on the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, an axially vertical first shaft connected to said table for rotating the same,

gear means engaged with said shaft for elevating the shaft and table, motor means, a second shaft rotatably driven by said motor means, said iirst shaft being slidably and nonrotatably engaged with said second shaft in all positions of elevation of the iirst shaft, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nipple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said passage -communicating with said central hole, sealing means in said nipple for-maintaining a hermetic seal with said tube while the pressure plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold plates and pressure plate rotate, and means on the table impelled by centrifugal force for holding the mold plates and pressure plate on the table when the table rotates and impelled by gravity tor releasing the mold plates and pressure plate when the table is stationary.

' 8. A centrifugal casting apparatus for casting jewelry pieces reproducing very ne mold details having widths approximating .010 of an inch, comprising a frame, a cylindrical pot-like base on said frame, said base having an open top, a -cover removably attached to the base for hermetically closing the same to constitute 'a vacuum vessel with said base, -said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively c-onnected to the crucible for tilting the same, heating means in the crucible -for keeping the metal molten in the crucible, means for supplying power to said heating means for energizing the same from outside the base, means external.

to the base and connected thereto for creating a vacuum in the vessel, valve means yon the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, means for rotating the table, means for elevating and lowering the table independently of the table rotating means so that the table rotates in all positions of elevati-on thereof, a -pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nipple having a passage for receiving said tube when the table, mold plates and pressure .plate are elevated, said passage communicating with said central hole, sealing means in said nipple for maintaining -a hermetic seal with said tube while the pressure plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold plates and pressure plate rotate, and means on the table impelled by centrifugal force for holding the mold plates and pressure plate on the table when the table rotates and impelled by gravity for releasing the mold plates and pressure plate when the table is stationary.

9. A centrifugal casting apparatus for casting iewelry pieces reproducing very ne mold details having widths approximating .010 of an inch, comprising: a fra-me, a stationary vacuum vessel on said frame, sa-id vessel having a bottom opening, a funnel -in said vessel communicating with said opening, a tube extending axially downward from the bottom of the vessel hermetically sealed therewith and communicating with said opening and funnel, a crucible in the vessel tiltably mounted -or pouring molten metal into the funnel, means operatively connected t-o the crucible lfor tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for creating la vacuum in the vessel and for relieving the vacuum therein, a table disposed below and parallel to the bottom of the vessel, means for elevating and lowering the table with respect to the vessel, means for rotating the table in all positions of elevation thereof with respect to the vessel, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nipple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said pas-sage communicating with said central hole, sealing means in said nipple for maintaining a hermetic seal with said tube while the pressure plate r0- tates with the table and mold plates, whereby molten metal deposited into the -funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, rnold plates and pressure plate rotate, a pair of upright arms on said table at diametrically opposed positions, a pair of posts pivotally attached to upper ends of the arms, weights on outer ends of the posts, inner ends of the posts extending radially .inward of the table for bearing down on the pressure pl-ate t-o hold the pressure plate and mold plates when the table is rotating and for releasing the pressure plate and rmold plates when the table is stationary.

10. A centrifugal casting apparatus for casting jewelry pieces reproducing very tine mold details having widths approximating .(llO of an inch, comprising Ia frame, a cylindrical pot-like base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and tunnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means 4operatively connected to the crucible Lfor tilting the same, heating means in the crucible .for keeping the metal molten in the crucible, imeans for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve means yon the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, means for rotating the table, means for elevating and lowering the table independently of the table rotating means so that the table rotates in all positions of elevation thereof, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nipple having a passage lfor receiving said tube when the table, mold .plates and pressure plate are elevated, said passage communicating with said central hole, sealing means in said nipple for maintaining fa hermetic seal with said tube While the pressure plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold plates and pressure plate rotate, a pair Kof upright arms on said table at dialnet-rically opposed positions, a pair of posts pivotally attached to upper ends of the arms, weights on outer ends of the posts, inner ends of the posts extending radially inward of the table for bearing down `on the pressure plate to S hold t-he pressure plate and mold plates when the table is rotating and for releasing the pressure plate and mold plates when the table is stationary.

11. A centrifugal Icasting apparatus for casting jewelry pieces reproducing very fine mold details having widths approximating .010 of an inch, comprising a frame, a

cylindrical pot-like base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively connected to the crucible for tilting the same, heating means in the crucible for keeping t'he metal molten in the crucible, means for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve means on the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, an axially vertical first shaft connected to said table for rotating the same, gear means engaged with said shaft for elevating the shaft and table, motor means, a second shaft rotatably driven by said motor means, said first shaft being slidably and nonrotatably engaged with said second shaft in all positions of elevation of the first shaft, a pair of separable mold plates on the table, said mold plates having radially arranged mold cavities therein, one of said mold plates having a central hole communicating with said cavities, a massive pressure plate on the mold plates, said pressure plate having an axial nipple extending toward the vacuum vessel, said nipple having a passage for receiving said tube when the table, mold plates and pressure plate are elevated, said passage communicating with said central hole, sealing means in said nipple for maintaining a hermetic seal with said tube while the pressure plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the mold cavities impelled by gravity and centrifugal force as the table, mold plates and pressure plate rotate, a pair of upright arms on said table at diametrically opposed positions, a pair of posts pivotally attached to upper ends of the arms, weights on outer ends of the posts, inner ends of the posts extending radially inward of the table for bearing down on the pressure plate to hold the pressure plate and mold plates when the table is rotating and for releasing the pressure plate and mold plates when the table is stationary.

12. A centrifugal casting apparatus for casting jewelry pieces reproducing very fine mold details having widths approximating .010 of an inch, comprising a frame, a cylindrical pot-like base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, ysaid tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively connected to the crucible for tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve means on the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, mold plates supported on said table, a pressure plate on the mold plates, means for rotating the table, and means independent of the table rotating means for elevating the table to establish communil@ cation between said tube and mold plates to receive molten metal therefrom, and for lowering the table to remove the mold plates from the table.

13. A centrifugal casting apparatus for casting jewelry pieces reproducing very fine mold details having widths approximating .010 of an inch, comprising a frame, a cylindrical pot-like base on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a bottom opening, a funnel in said base communicating with said opening, a tube extending axially downward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively connected to the crucible for tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for supplying power to said heating means for energizing the same from outside the base, means extern-al to the base and connected thereto for creating a vacuum in the vessel, valve means on the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, mold plates supported on said table, a pressure plate on the mold plates, means for r0- tating the table, and means independent of the table rotating means for elevating the table to establish communication between said tube and mold plates to receive molten metal therefrom, Iand for lowering the table to remove the mold plates from the table, and means on the table impelled by centrifugal force for holding the mold plates and pressure plate on the table when the table rotates and impelled by gravity for releasing the mold plates and pressure plate when the table is stationary.

14. A centrifugal casting apparatus for casting jewelry pieces reproducing very line mold details having widths approximating .010 of an inch, comprising a frame, a cylindrical pot-like base `on said frame, said base having an open top, a cover removably attached to the base for hermetically closing the same to constitute a vacuum vessel with said base, said base having a `bottom opening, a funnel in said base communicating with said opening, a tube extending axially Idownward from the bottom of the base and hermetically sealed therewith, said tube communicating with said opening and funnel, a crucible in the base tiltably mounted for pouring molten metal into the funnel, means operatively connected to the 'crucible for tilting the same, heating means in the crucible for keeping the metal molten in the crucible, means for supplying power to said heating means for energizing the same from outside the base, means external to the base and connected thereto for creating a vacuum in the vessel, valve means on the cover for relieving the vacuum in the vessel, a table rotatably supported below and parallel to the bottom of the base, mold plates supported on said table, a pressure plate on the mold plates, means for rotating the table, and means independent of the table rotating means for elevating the table to establish communication between said tube and mold plates to receive molten metal therefrom, and for lowering the table to remove the mold plates from the table, a pair of upright arms on said table at diametrically opposed positions, a pair of posts pivotally attached to upper ends of the arms, weights on outer ends of the posts, inner ends of the posts extending radially inward of the table for bearing down on the pressure plate to hold the pressure plate and mold plates when the table is rotating `and for releasing the pressure plate and mold plates when the table is stationary.

`15. A `centrifugal casting apparatus, comprising: a frame, a stationary vacuum vessel on said frame, said vessel having a bottom opening, a funnel in said vessel communicating with said opening, a tube extending axially downward from said opening lfor receiving molten metal from the funnel, a crucible in said vessel tiltably mounted for pouring molten metal into the funnel, heating means in the Crucible for keeping the metal molten in the cru cible, means for maintaining a vacuum in said Vessel, a table disposed below and parallel to the bott-om of the vessel, mold plates supported on said table, sa-id mold plates having cavities therein, means for elevating and lowering the table with respect t0 the vessel, means for rotating the table in all positions of elevation with respect to the Vessel, a massive pressure plate supportable by said mold plates on the table, said pressure -plate having :a nipple extending axially upward in axial alignment with said tube, sealing means in said nipple for maintaining a hermetioseal with said tube While the plate rotates with the table and mold plates, whereby molten metal deposited into the funnel will run into the cavities in the mold plates impelled by gravity and centrifugal force as the table, pressure plate and mold plates rotate, and means on the table for automatically engaging and holding the mold plates while the table rotates and for automatically releasing the mold plates when the table is stationary, the last-named means comprising a pair of upright arms on said table at diametrically opposed positions, a pair of posts pivotally attached to upper ends of the arms, weights on -outer ends of the posts, inner ends of the posts extendl ing radially inward of the table for bearing down on the pressure plate to hold the pressure plate and mold plates when the table is rotating and for releasing the pressure plate and mold plates when the table is stationary.

References Cited by the Examiner UNITED STATES PATENTS 2,829,408 4/ 195 8 Shuek 22-65 3,052,001 9/ 1962 Brennan 22-65 3,199,158 8/ 1965 Rigatti-Luehini 22--73 X I. SPENCER OVERHOLSER, Primary Examiner.

R. S. ANNEAR, Assistant Examiner. 

1. ACENTRIFUGAL CASTING APPARATUS, COMPRISING: A FRAME, A STATIONARY VACUUM VESSEL ON SAID FRAME, SAID VESSEL HAVING A BOTTOM OPENING, A FUNNEL IN SAID VESSEL COMMUNICATING WITH SAID OPENING A TUBE EXTENDING AXIALLY DOWNWARD FROM SAID OPENING FOR RECEIVING MOLTEN METAL FOR THE FUNNEL, A CRUCIBLE IN SAID VESSEL TILTABLY MOUNTED FOR POURING MOLTEN METAL INTO THE FUNNEL, HEATING MEANS IN THE CRUCIBLE FOR KEEPING THE METAL MOLTEN IN THE CURCIBLE, MEANS FOR MAINTAINING A VACUUM IN SAID VESSEL, A TABLE DISPOSED BELOW AND PARALLEL TO THE BOTTOM OF THE VESSEL, MOLD PLATES SUPPORTED ON SAID TABLE, SAID MOLD PLATES HAVING CAVITIES THEREIN, MEANS FOR ELEVATING AND LOWERING THE TABLE WITH RESPECT TO THE VESSEL, MEANS FOR ROTATING THE TABLE IN ALL POSITIONS OF ELEVATION WITH RESPECT TO THE VESSEL, A MASSIVE PRESSURE PLATE SUPPORTABLE BY SAID MOLD PLATES ON THE TABLE, SAID PRESSURE PLATE HAVING A NIPPLE EXTENDING AXIALLY UPWARD IN AXIAL ALIGNMENT WITH SAID TUBE, SEALING MEANS IN SAID NIPPLE FOR MAINTAINING A HERMETIC SEAL WITH SAID TUBE WHILE THE PLATE ROTATES WITH THE TABLE AND MOLD PLATES, WHEREBY MOLTEN METAL DEPOSITED INTO THE FUNNEL WITH RUN INTO THE CAVITIES IN THE MOLD PLATES IMPELLED BY GRAVITY AND CENTRIFUGAL FORCE AS THE TABLE, PRESSURE PLATE AND MOLD PLATES ROTATE, AND MEANS ON THE TABLE FOR AUTOMATICALLY ENGAGING AND HOLDING THE MOLD PLATES WHILE THE TABLE ROTATES AND FOR AUTOMATICALLY RELEASING THE MOLD PLATES WHEN THE TABLE IS STATIONARY. 